nouveau: nv10: check NULL pointers

diff --git a/src/mesa/drivers/dri/nouveau/nv10_state.c b/src/mesa/drivers/dri/nouveau/nv10_state.c
index 94525ba2a80504c7294567ea858690ac3516acd5..b63893d05c44931a37d343046e1d6c158904c5a0 100644 (file)
--- a/src/mesa/drivers/dri/nouveau/nv10_state.c
+++ b/src/mesa/drivers/dri/nouveau/nv10_state.c
@@ -253,8 +253,12 @@ static void nv10DepthRange(GLcontext *ctx, GLclampd nearval, GLclampd farval)
        nouveauContextPtr nmesa = NOUVEAU_CONTEXT(ctx);
 
        GLfloat depth_scale = 16777216.0;
-       if (ctx->DrawBuffer->_DepthBuffer->DepthBits == 16) {
-               depth_scale = 32768.0;
+       if (ctx->DrawBuffer) {
+               if (ctx->DrawBuffer->_DepthBuffer) {
+                       if (ctx->DrawBuffer->_DepthBuffer->DepthBits == 16) {
+                               depth_scale = 32768.0;
+                       }
+               }
        }
 
        BEGIN_RING_CACHE(NvSub3D, NV10_TCL_PRIMITIVE_3D_DEPTH_RANGE_NEAR, 2);